- "You are travelers. You come seeking answers. Hear my voice. Heed my warning. The knowledge you seek was not intended for mortal man. Breathe deeply. The power of the vapors will transport you. Let yourself fall through the ages. Through time and space itself. And pray for your safe return..."
- — The Oracle in IX intro cutscene.
The Oracle (also known as Medusa) is a character featured in the Chaos story of Treyarch's Zombies. She can be heard in the map IX, and physically appears in the map Ancient Evil from Call of Duty: Black Ops 4.
Sometimes after the 4th century BC, Perseus arrived in Delphi and demanded the Oracle to activate the Sentinal Trial. She refused, auguring disaster. To force her to comply with his demands, Perseus imprisoned her two sisters, Stheno and Euryale. Fearing that he would hurt them, the Oracle agreed to activate the Artifact. She was then tied to her chair inside the Temple of Apollo.
At first, the Oracle helped Perseus and his men but as time passed she stopped helping them. As punishment, Perseus beheaded the Oracle's sisters.
The trial ran for centuries, with Prima Materia corrupting the entire city. When Scarlett Rhodes, Stanton Shaw, Diego Necalli and Bruno Delacroix entered Delphi in 1912, the Oracle begged them to free her, and in return she would free Alistair Rhodes. With the help of the Oracle, they completed the trial defeating Perseus and obtained the key to free the Oracle.
When they returned to the Oracle, she opened a secret entrance and told them Alistair was free. Bruno, Shaw and Diego left to help Alistair and Scarlett stayed to free the Oracle. When they reached the end of the tunnel, Bruno, Shaw and Diego found out that Alistair and several cultists were turned into stone and Diego ran off to Scarlett. While the other three were gone, the Oracle mesmerized Scarlett to learn about the modern world. When Diego arrived, the Oracle, who revealed herself as Medusa, tried to attack him but he hid behind one of the pillars. Medusa released Scarlett, who lost consciousness and picked one of the cultists' masks to protect herself from the Prima Materia. She witnessed a vision in the Eternal Flame and, before leaving the Temple of Apollo, she declared that she will open the library and the world will be hers.